When my headphone jack started failing I investigated the issue on-line. I found several similar cases on line and thought this would be a breeze to get fixed on my warranty. It was a well known issue with the sensor inside the iPhone detecting whether the headphone was plugged in. So I sent in the phone for repairs but apparently the water sensor on the docking connector was slightly "not white" (translated: they believe that the water sensor is triggered) thus rendering the warranty void.
The repair service log showed me that the repairman used less than 2 seconds deciding that my warranty was void, even though the phone was working perfectly - except for this error with the headphone jack. This "2 second job" gave 3 alternatives for me online:
1) scrap the phone, price: free
2) return the phone unrepaired, £70 service fee
3) repair phone (new phone £550)
I chose alternative 2, it was the only real option for me.
Adding more sensors/detectors is probably great for Apple. But they need to inform and disclose this in their user manuals, clearly visibly in your warranty. I didn't find out about the water sensors until after it was repaired.
The problem with these sensors is if they are triggered without you doing anything wrong to the phone, and this mean that if a sensor is triggered and you get a hardware error not at all related to the sensor being triggered you will not be able to have your device fixed because the warranty is void.
Another important aspect is that any sensor could also be triggered BEFORE you even open the box. WTH are you supposed to do if the phone is pre-broken. How can you check your sensors is not triggered?
